Sounds like you are doing all you can on the neighbour front, short of sneaking out and replacing any food they put out (probably not advisable if you wanted to stay on friendly terms!).
Anyway – is your vet a hog friendly one? I hate to say it but most don’t know enough about hogs, as the wildlife course they have, which at least gives them a starting point, is currently still ‘optional’ with additional cost for veterinary students. a local carer or rescue will point you in the direction of the bests vets to use, ie the ones they use – or may offer to take a look if you were worried. its an education getting involved with these people – their knowledge and network is immense! you can find them on hedgehog bottom website via the map or BHPS website.